Hydrocarbon conversion process



D. READ, JR

HYDROCARBON CONVERSION PROCESS Filed April 30, 1945 M0709 magg ww NSN@Jan. 27, 1948.

Patented Jan. 27, 1948 HYDROCARBON CONVERSION PROCESS Davis Read, Jr.,Downers Grove, lll., assixnor to Universal Oil Products Company,Chicago, lll., a corporation of Delaware Application April 30, 1945,Serial No. 591,035

(Cl. 19d-52) 11 Claims.

conversion of organic compounds and is more specifically concerned withthe catalytic con version of organic compounds in the presence ofspherical catalyst particles.

In recent years catalytic processes have been employed extensively inorganic reactions, particularly in the conversion of hydrocarbon oils tochemicals or motor fuels, for example, the cracking of high boiling oilsto gasolines, dehydrogenation of saturated hydrocarbons to olenic oraromatic hydrocarbons, conversion of butanes and butenes to butadiene,and ethylbenzene to styrene. Some of the earlier methods of employingsolid catalysts consisted of passing the hydrocarbons or other organiccompounds through a reaction zone in which the catalyst was deposed iniixed bed relationship to the incoming reactants, or conducting thereaction by suspending minor amounts of the catalyst in granular orpowdered form in a stream of reactants which is thereafter passedthrough a heating zone maintained at the desired conditions to producethe desired reaction.

The present invention consists of animprovement in a method ofconducting the latter type of operation. The basic disadvantages of theuse of powdered or granular catalyst in suspension in the reactants are,ilrst, erosion of the equipment through which the catalyst is passed,and secondly, the rapid rate of attrition of the catalyst particles tomore nely divided materials.

It is an object of the present invention to provide an economicalprocess employing a solid catalyst in suspension in the reactants with aminimum of erosion of the equipment and a low rate of attrition of thecatalyst particles.

In one embodiment the present vinvention consists of a catalytic processfor the conversion of organic compounds which comprise subjecting saidorganic compound at conversion conditions of temperature and pressure tothe action of a spherical shaped catalyst suspended therein.

The use of spherical catalyst particles eliminates to a large extent thedifiiculty of erosion of the equipment. Powdered or granular cata- .lystwhen passed at a rapid rate through the equipment causes considerableerosion due primarily to the sharp jagged edges of the individualparticles or granules producing an eectv similar to that obtained whensand blasting metals. The spherical particles ow smoothly through theequipment without contacting the surfaces of the equipment with jaggededges thereby reducing erosion to a minimum.

As evidenced by data presented hereinafter in this specification, therate of attrition of the spherical particles is substantially lower thanthat of powdered or granular materials. This decreased vattrition notonly permits the maintenance of a more uniform catalyst size throughoutthe reaction zone, but also has the attending advantage of decreasingcatalyst losses which ordinarily accompany attrition by decreasing theformation of very ne powders which are lost by entrainment in theoutgoing'reactants.

The process of the present invention may be satisfactorily employed invarious organic conversion processes and in particular in hydrocarbonconversion processes, such as the catalytic cracking of higher boilingoils to lower boiling oils, catalytic reforming of straight-rungasolines, catalytic dehydrogenation of paramnic, monoolenic ornaphthenic hydrocarbons, and the catalytic treatment of olenic gasollnesto either isomerize the olens contained therein or to lower the quantityof oleiins present by hyn drogen transfer or other similar reactions.The process is also applicable to operations in which alkyl groups aretransferred from a polyalkylated aromatic or naphthenic hydrocarbon to aless alkylated compound, such as for example, the formation ofmonoethylbenzene from diethylbenzene and benzene. o

The catalysts which may be employed in the present invention comprisesynthetically prepared composites of silica-alumina, silicamagnesia.silica-th'oria, silica-zirconia, silica-boron oxide, or a compositecontaining silica-alumina and one or more of the oxides of thorium,boi-on, zirconium, titanium, magnesium. Catalysts comprising oxides orsuldes of vanadium, molybdenum, chromium and tungsten, either alone orin admixture with one another, preferably supported on materials such assilica or alumina can also be employed.

These catalysts may be formed in spherical shapes by various methods.Methods which are particularly applicable consist of forming a sol orgel of the compounds and suspending it in a liquid or gaseous mediumunder controlled conditions to form a rigid sphere which can besubsequently puried, washed and impregnated by some of the othercompounds. For example, a slurry of silica hydrogels may be spray driedto form smaller spherical particles and the puried spheres impregnatedwith laluminum'or magnesium salts to form a composite catalyst.

The operating conditions employed, such as l temperature and pressure,will of course be deline 24 and valve 25 into pump 8l which dissimilarto those employed in the catalytic' cracking operations. However, if theoperation is the so-called hydroforming operation, i. e., catalyticreforming in the presence of hydrogen, the pressure range will be of theorder of from about 100 to about 1000 pounds per square inch gage.

The operation of the present invention will be more clearly described inthe following description of the attached drawing which illustrates aconventional sideelevation of one type of apparatus in which the objectsof the invention can be accomplished. This description clearly indicatesthe advantages of employing the spherical catalyst, particularly as tothe simplicity of the catalyst recovery system employed in contrast tothose necessary when employing powdered or granular catalyst materials.

In order to simplify explanation of the draw# ing, the description willbe limited to the catalytic cracking operation and standard equipment,such as condensers, coolers. etc., have been eliminated from theHowever, it is not intended that this description limit the generallybroad scope of this invention in any manner whatsoever.

It will be noted that the apparatus `described. provides a method ofintroducing the catalyst into the system without the use of a pump. thussimplifying the operation and eliminating the operating'diflicultiesusually encountered when` which discharges through line 4 containingvalve 5 and is commingled with spherical catalyst particles obtained, ashereinafter set forth, within line 4 and the mixture introduced intoreaction zone 3 which consists ofa heating coil dlsposed within furnace1 wherein the mixture is heated to conversion conditions. The reactionproducts leave coil 9 through line 3 containing valve 9 l and aredirected into cyclone separator l0 wherein the spherical crackingcatalyst. for example a synthetic composite of silica-alumina, isseparated from the hydrocarbons. The separated catalysts dropsdownthrough line i I into catalyst separator I2. Reaction products'arewithdrawn from the cyclone separator through line I1 containing valve I3and are directed into gas sep'- arator I9 wherein the light hydrocarbongases formed during the reaction are separated from the liquidhydrocarbons. These gases which include butanes, propanes. ethane andsmall amounts of methane in 'addition to ethylene, propylene andbutylenes, are withdrawn from gas separator I9 through line 20 and aportion discharged from the system through valve 2i and line 21 with theremaining portion being circulated through line 22 containing va'lve 23and employed after passage through compressor 49 fas a means forpressurizing catalyst hoppers 59, 60 and 3| as hereinafter described.The liquid products in gas separator I9 are withdrawn through chargesthrough valve 85 into fractionator 29 wherein the liquid productsarestabilized by the removal of a portion of light gases. The liquidproducts from fractionator 28 are withdrawn through line 29 containingvalve '30 into the suction side of pump 92 which discharges throughvalve 33 into fractionator 3I wherein they are separated into a.gasoline fraction and a bottoms fraction, the gasoline fraction beingrecovered overhead through line 32 containing valve 33. The

bottoms fraction comprising high boiling residue and unconverted gas oilis withdrawn through line 34 containing valve 35 and may be recovered asa product of the reaction, or in some cases may be recycled back to thereaction zone.

The gaseous hydrocarbons removed overhead from fractionator 25 passthrough line 21 containing valve 23 into line 49 where they arecommingled with the gases from cyclone separators 53. 54 and 5 5 and maybe passed to the fuel system or recovered as a product of the reaction.

The spheres collected in the bottom of catalyst separator I2 aretransferred through line, I3 and' adjustable orifice valve I4 .to one ofthe cyclone separators 53, 54 and 55 at the top of hoppers 59. 60 and5I, respectively. This is accomplished alyst spheres are suspended inrecycle gas supplied from line 22 through line rI5 having valve I6. Inthe operation of the present process, one of the hoppers is employed tocollect the catalyst while another, after being pressured with recyclevgas to a pressure above the reaction zone pressure. feeds theregenerated catalyst through an adjustable orifice into the recycle gasstream and thence to the reaction zone, and the third hopper acts as aregenerator for the spent catalyst. The arrangement herein presentedpermits the use of any one of the hoppers as a feeder to the recycle gasstream, catalyst storage hopper or regenerator hopper and permits atruly continuous operation. To pressurize the hoppers, recycle gas fromline 22 is compressed'in compressor 48 and supplied to the hoppers from'manifold line 50, the gas being introduced to hopper 59 through line 51having valve 53, tolhopper 60 through line 52 having valve 56 and tohopper 6I through valve 5I in line 5 0. A portion of the compressed gasemployed for regeneration, passes through line i 14 into line 3|' fromwhich it is directed through valves 30' and 9| into the suction side ofvcompresser 54 which discharges through valve 6,5 into line 61' and isrecirculated through the hopper in admixture with regulated amounts ofair intro duced through line 62 containing valve E3. In this manner theoxygen concentration can be maintained at a comparatively low value toprevent too rapid burning with the attending temperature rise lwhich maydamage the catalyst.

The catalyst employed is somewhat thermophobic and temperatures inexcess of about 1400 F. tend to cause a deterioration of the catalystactivity ordinarily by decreasing the surface area of the catalyst.Steam may be introduced for purging pur- 2. A process for crackinghydrocarbons which comprises passing a stream of hydrocarbon containingsuspended spherical particles of catalyst through a cracking zonemaintained at crack poses through line li containing valve l2. Exingconditions, separating catalyst from the cess gases may be dischargedfrom line 8i' to .cracked products,- fractionating lsaid cracked theatmosphere as shown on the drawing to mainproducts to separate a streamof normally gasetain a substantially constant pressure onk the ousproducts, suspending said separated catalyst hopper during regeneration.The products from in at least a portion of the stream of normally thepurging operation which will consist of hy- 10 gaseous products,supplying the resultant susdrocarbons retained on the lcatalyst may Vbepension to a catalyst regenerating zone and withdrawn through line i1containing valve 79 therein separating catalyst from the gaseous to anysuitable separating equipment to separate products and retaining theseparated catalyst. the hydrocarbons from the steam condensate. stoppingthe ow of said suspension into the re- The regenerating gases een bedirected into any generating zone after a predetermined time and one ofthe hODpers by Opening the desired valve. regenerating the catalysttherein contained at either valve 66. l0 or 68. regenerating gas passingrelatively'low pressure, thereafter supplying anthmueil lines 62 5l and59' other portion of said stream of gaseous products The followingexample presents data illusilalj under elevated pressure to saidregenerating zone ing the Comparative rates 0f erosion and attii" 2o toprovide suiiicient pressure therein to force said lian When employing a'Powdered catalyst and a catalyst in said stream of hydrocarbon prior toSpherical atalyst f cracking of the latter, and then discharging theExample catalyst from the regenerating zone into the last- The rate ofattrition is measured as the weight named stream under the pressure thusProvided per cent loss of catalyst per hour per pound of in theregenerating zone. catalyst circulated per hour. The extent of ero- 3. Aprocess for catalytically reforming hydrosion was determined bycirculating the catalyst carbons which comprises passing a stream ofgaswith air through copper metal tubes and was olinehydrocarbonscontaining suspended spherimeasured as the weight per centof metal loss per cal particles of catalyst through a conversion hourper pound of catalyst circulated per hour. zone maintained at reformingconditions, sepa Attrition Erosion Wt. Wt. Per cent Per cent Cat Cat.Loss Metal Loss Avg. Air Loa per Hr. per Hr. Mesh Rate Lnper size soFECF Lb. Cat. Lb. Cat. Cir. per Hr. Cir. per Hr. x10-4 x10-l Powdered Cat70 32. 3 1.04 80 30 Spherical Cat 70 32. 3 1. 06 3. 6 5

It will be noted from the above data that the rating catalyst fromcatalytically-reformed prodrate of attrition of the powdered catalyst isapucts, fractionating said catalytically reformed proximately 22 timesthat of the spherical cataproducts to separate a stream of normallygaselyst. It will also be noted that the erosion rate ous products.suspending said separated catalyst of the powdered catalyst was 6 timesthat of the in at least a portion of the stream of normally sphericalcatalyst. gaseous products, supplying the resultant sus- I claim as myinvention: pension to a, catalyst regenerating zone and 1. A process forconverting hydrocarbons therein separating catalyst from the gaseouswhich comprises passing a stream of hydrocarproducts and retaining theseparated catalyst, bons containing suspended spherical particles ofstopping the flow of said suspension into the re catalyst through areaction zone maintained at generating zone after a predetermined timeand conversion conditions, separating catalyst from regenerating thecatalyst therein contained at conversion products, fractionating saidconverrelatively low pressure. thereafter supplying ansion products toseparate a stream of normally other portion o said stream of gaseousproducts gaseous products, suspending said separated catunder elevatedpressure to said regenerating zone alyst in at least a portion of thestream of norto provide sumcient pressure therein to force said mallygaseous products, supplying the resulto0 Catalyst into said stream ofhydreearben prior ant suspension to a catalyst regenerating zone to thecatalytic reforming of the latter, and then and therein separatingcatalyst from the gaseous discharging the catalyst from the regeneratingproducts and retaining the separated cata1yst, zone into the last-namedstream under the presstopping the flow of said suspension into the re-Sure thus prevded in the regenerating zone. generating zone after apredetermined time and 4 A process fOr the Catalytic dehydregenatienregenerating the catalyst therein contained at of a dehydrogenetablehydrocarbon which comrelatively low pressure, thereafter supplyinganprises Passing a stream of hydrocarbon containother portion of saidstream of gaseous products ing suspended spherical Particles 0f edehydreunder elevated pressure to said regenerating zone genatienCatalyst thrOugh a Conversion Zone to provide suiicient pressure thereinto force said 7o maintained at dehydregenaten conditions, Sepacatalystinto said stream of hydrocarbons prior rating catalyst fromdehydrOgeneted PrOdllCtS, to conversion of the latter, and thendischarging fractionating Said dehydrogenated products to the catalystfrom the regenerating zone into the Separate a stream of normallygaseous products, last-named stream under the pressure thusprosuspending said separated catalyst in at least vided in theregenerating zone. a portion of the stream of normally gaseous products, supplying the resultant suspension to a catalyst regenerating zoneand therein separating catalyst from the gaseous products and retainingthe separated catalyst, stopping the ilow of said suspension into theregenerating zone after e. predetermined time and regenerating thecatalyst therein contained at relatively low pressure, thereaftersupplying another portion of said stream of gaseous products: underelevated pressure to said regenerating zone to provide sufficientpressure therein to force said catalyst into said stream of hydrocarbonprior to catalytic dehydrogenation of the latter, and then dischargingthe catalyst from the regenerating zone into the last-named stream underthe pressure thus provided in the regenerating zone.

5. The process of claim 2 further characterized in that said catalystcomprises a silica-alumina composite.

6. 'I'he process of claim 3 further characterized in that said catalystcomprises alumina-chromia.

7. The process of claim 4 further characterized in that said catalystcomprises alumina-chroma.

8. A hydrocarbon conversion process which comprises introducing to areaction zone a stream ot hydrocarbons containing suspended sphericalcatalyst particles and therein subjecting the hydrocarbons to conversionconditions in the presence of the catalyst, separating resultantconversion products from the catalyst particles and fractionating thesame to separate normally gaseous hydrocarbon products from normallyliquid hydrocarbons, suspending. separated catalyst particles in aportion of said'gaseous products, transferring said separated catalystparticles by means of the resultant suspension to a regenerating zoneand retaining the transferred catalyst in said regenerating zone until asubstantial body of catalyst particles has been accumulated therein,thereafter interrupting the transfer of said catalyst particles to saidregenerating zone and regenerating said body of catalyst particles insitu at relatively low pressure, subsequently introducing a secondportion of said gaseous products to said regenerating zone in suilicientamount 'situ at relatively low pressure. subsequently in' afterdischarging said body of regenerated cata-I lyst particles under theincreased pressure from said regenerating zone into a'thlrd portion ofsaid gaseous products to form a suspension therein,

`and commingling said last named suspension with said streamorhydrocarbons being supplied to said reaction zone.

10. A hydrocarbon conversion process which comprises introducing to e.reaction zonea stream o! hydrocarbons containing suspended sphericalcatalyst particles and therein subjecting the hydrocarbons to conversionconditions in the presence of the catalyst,- separating the resultantconversion products from contaminated catalyst particles, fractionatingsaid conversion products to separate a hydrocarbon gas from liquidhydrocarbons. suspending said contaminated catalyst particles in a,portion of said hydrocarbon gas, introducing said contaminated catalystparticles by means of theresultant suspension to one of a plurality ofcatalyst storage zones and retaining the transferred catalyst thereinuntil a substantial body of contaminated catalyst particles hasaccumulated therein, thereafter diverting the introduction of lsaidcontaminated catalyst particles te another of said storage zones,introducing an oxygen-containingregenerating gas into the storage zonecontaining said body of contaminated catalyst particles `andregenerating to increase the pressure in this zone to above thatprevailing in the reactionzone. and then discharging said body ofregenerated catalyst particles under the increased pressure from saidregenerating zone into said stream of hydrocarbons being supplied to thereaction zone.'

' discharging catalyst whereby to provide a con- 9. A hydrocarbonconversion process which comprises introducing to a reaction zone astream of hydrocarbons containing suspended spherical catalyst particlesand therein subjecting the hydrocarbons to conversion .conditions in thepresence or the catalyst, separating resultant conversion products `fromthe catalyst particles and fractionating .the same to separate normallygaseous hydrocarbon products from normally liquid hydrocarbons.suspending separated catalyst particles in a portion of said gaseousproducts, transferring said separated catalyst particles by means of theresultant suspension to a regenerating zone and retaining thetransferred catalyst in said regenerating zone until a substantial bodyof catalyst particles has been accumulated there'. in, thereafterinterrupting the transfer of said catalyst particles to saidregenerating zone and regenerating ysaid body or -catalyst particles inthe latter in situ, thereafter diverting the introduction of saidregenerating gas to another of said storage zones, introducing a secondportion of said hydrocarbon gas to the storage zone containing the bodyof regenerated catalyst particles to increase the pressure therein,discharging.

said body of regenerated catalyst particles under the increased pressurefrom said last-named stor.. age zone into said` stream of hydrocarbonsbeing supplied to said reaction zone, and successively repeating in eachof said storage zones the steps of transferring. regenerating,repressuring, and

tinuous process of hydrocarbon conversion and catalyst regeneration.

11. The process of claim 10 further characterized in that said body ofregenerated catalyst particles is discharged into e, third portion ofsaid hydrocarbon gas to form a suspenslonthereim and the last-.namedsuspension is commingled with said stream of-hydrocarbons being suppliedto said reaction zone.

' Davis Jr.

REFERENCES CITED The following references are or record in the nle ofthis patent:

UNrrEn STATES PATENTS Number Name Date 2,305,569 Degnen Dec. l5, 19422,338,606 Voorhees Jan. 4, 1944 2,379,711 Hemminger July 3; 19452,384,943 Marisic Sept. 18, 1945 2,384,358 Tyson Sept. 4, 1945

